Field
Exemplary embodiments relate to a touch panel and a method for driving a touch panel.
Discussion of the Background
In general, display devices (i.e., a liquid crystal display and an organic light emitting display), portable transmission devices, and other information processing devices perform a function by using various input devices. Recently, input devices are more frequently including a touch sensing device.
A touch sensing function is used to determine contact information (i.e., whether an object approaches or touches a screen) and a touch location by sensing changes (i.e., changes in pressure, charge, and light) that are applied to the screen of the display device when a user writes text or draws figures on or near the screen using the object (i.e., a finger or a touch pen). The display device receives an image signal based on the contact information to display an image.
Such a touch sensing function may be realized through a touch electrode. The touch electrode may be classified into various types such as a resistive type, a capacitive type, an electromagnetic resonance (EMR) type, and an optical type.
In the case of the resistive touch electrode, two electrodes that face each other and are separated from each other may contact each other as a result of pressure from a finger. When the two electrodes contact each other, a contact position is known by recognizing changes of voltage induced by changes of resistance at the position.
The capacitive touch electrode includes a sensing capacitor formed of a plurality of touch electrodes for transmitting sensing signals. The capacitive touch electrode senses a change in capacitance of the sensing capacitor generated when a conductor such as a finger approaches the sensor to determine existence of a touch and a touch position.
The touch sensor may be formed on the touch panel and attached to the display device (add-on cell type). The touch sensor may be formed out of a substrate of the display device (on-cell type). The touch sensor may also be formed in the display device (in-cell type). The display device including the touch sensor may detect whether an object (i.e., a finger or a touch pen) touches the screen and the touch location information of the object. As a result, the display device may display an image corresponding to the touch.
The above-noted various types of touch electrodes are disposed in a touch region, include a plurality of touch electrodes for sensing touches, and include a connection wire connected to the touch electrodes. The touch region may overlap a display area. The connection wire may transmit a sensing input signal to the touch electrode or a sensing output signal of the touch electrode generated according to the touch to a sensing signal controller.
Conventionally, the touch driving signal for sensing a touch was applied in a uniform manner, wasting power consumption. Further, the touch driving signal was applied uniformly regardless of a user was using the touch panel or would be imminently using the touch panel, wasting further power consumption.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.